Open .cir Files Online — Free NGSPICE Viewer
Open NGSPICE File Online — Free & Instant
No signup required. Works in your browser.
📁 Drag & drop your file here
or click to browse • Max 100MB
✅ Free • ⚡ Instant • 🔒 Secure • 💻 No install
What Is a .cir File?
A .cir file is a scientific format known as NGSPICE. ngspice Circuit File This format is created by ngspice and is widely used by researchers and academics.
NGSPICE files contain structured scientific data that requires compatible software to open. With OpenAnyFile, you can analyze and visualize .cir files directly in your browser without installing any software.
How to Open .cir Files Online
- Visit OpenAnyFile NGSPICE page
- Drag and drop your .cir file onto the upload area, or click "Browse" to select it
- OpenAnyFile automatically detects the NGSPICE format using magic byte analysis
- View, analyze, and analyze and visualize your file contents in the browser
- Optionally convert to TXT or download
Software That Opens .cir Files
.cir files are primarily created by ngspice. In the scientific space, you may encounter .cir files from third-party tools, online converters, or export functions. Regardless of the source, OpenAnyFile handles them all.
Open .cir on Different Platforms
- Windows: Use the original software or upload to OpenAnyFile for instant access
- macOS: Preview may not support .cir — use OpenAnyFile as a universal viewer
- Linux: Open-source alternatives exist, or use OpenAnyFile in any browser
- Mobile (iPhone/Android): OpenAnyFile works on all mobile browsers
Common .cir File Problems
SPICE dialect differences
Other common issues include: your OS not recognizing the file extension, the file appearing corrupted after download, or lacking the required software. OpenAnyFile bypasses all these issues with universal format detection.
Convert NGSPICE to Other Formats
NGSPICE files can be converted to 1 formats including TXT.
Related Scientific Formats
If you work with .cir files, you may also encounter these scientific formats:
- ABAQUS_INP (.inp) — Open & convert .inp files online
- ABF (.abf) — Open & convert .abf files online
- ABINIT (.abi) — Open & convert .abi files online
- AMBER (.prmtop) — Open & convert .prmtop files online
- Amber Topology (prmtop) — Open & convert prmtop files online
- Amber Trajectory (mdcrd) — Open & convert mdcrd files online
- ANSYS_MECH (.mechdat) — Open & convert .mechdat files online
- ANTEX (.atx) — Open & convert .atx files online
- ASC_LTSPICE (.asc) — Open & convert .asc files online
- ASYMPTOTE (.asy) — Open & convert .asy files online
Popular NGSPICE Conversions
Frequently Asked Questions
What is a .cir file?
A .cir file is a scientific format called NGSPICE. ngspice Circuit File
How do I open a .cir file without installing software?
Upload your .cir file to OpenAnyFile. Our browser-based tool instantly detects and displays it — no downloads needed.
What program creates .cir files?
.cir files are typically created by ngspice.
Can I convert .cir to another format?
Yes. OpenAnyFile converts .cir to TXT.
Is it safe to open .cir files online?
Yes. OpenAnyFile processes files in a secure, isolated environment. Files are automatically deleted and all transfers use HTTPS.
Can I open .cir on my phone?
Yes. OpenAnyFile works on all mobile browsers including iPhone and Android.